Cardinal Keith O’Brien, an outspoken opponent of gay marriage and formerly the most senior cleric in the UK, has confessed to inappropriate sexual behaviour after being accused of making homosexual advances towards young men.

The Cardinal confessed that his “sexual conduct has fallen below the standards expected” and asked for forgiveness from those he had “offended”, as well as the entire Catholic Church and the people of Scotland, reports The Telegraph. He has said he would now withdraw completely from public life

Cardinal O’Brien was the former Archbishop of St Andrews and Edinburgh and only a week ago was set to take part in the election of the next Pope.

"I wish to [...] admit that there have been times that my sexual conduct has fallen below the standards expected of me as a priest, archbishop and cardinal,” he said.

His admission came as fresh details emerged of the allegations of “inappropriate” behaviour against him by four men – three priests and one former priest, which included attempting to touch, kiss and have sex with them.

One of the accusers also claimed that he had been warned not to let the allegations become public or risk damaging the Church.

A sworn statement said: “He started fondling my body, kissing me and telling me how special I was to him and how much he loved me."

Cardinal O’Brien was the most high-profile opponent of gay marriage in Britain, calling it as a “grotesque subversion”. He warned that the plans for a law change would open the way to “further aberrations” and said society “would be degenerating even further than it already has into immorality.”

The Cardinal said in his statement: “To those I have offended, I apologise and ask forgiveness.

“To the Catholic Church and people of Scotland, I also apologise.

“I will now spend the rest of my life in retirement. I will play no further part in the public life of the Catholic Church in Scotland.”